Evaluation of the Amount of Residual Radioactivity

The evaluation of the amount of residual radioactivity means to evaluate the amount of radioactive materials that have been generated by the operation of the nuclear reactor and remained in the reactor facility. Because its evaluation results become the basic data for the evaluation of the radioactive waste, safety assessment at the time of dismantling, exposure assessment at the time of dismantlement work and the economic evaluation, etc., it is important to accurately evaluate them as far as possible. In "Fugen," for the concentration, nuclide, property and location of the remaining radioactive materials, we evaluate them by dividing into "amount of radioactivity" and "amount of contamination."

For evaluating the amount of radioactivity, we evaluate it using the technique of confirming the validity of the analysis with the sampling measurement of actual samples by making the evaluation with analysis as a base.

For evaluating the amount of contamination, because it is difficult to accurately evaluate it by calculation unlike the amount of radioactivity, we evaluate it based on the measurement by sampling, contamination history survey by the radiation control records, etc.